CN2572638Y - Overvoltage protective circuit - Google Patents
Overvoltage protective circuit Download PDFInfo
- Publication number
- CN2572638Y CN2572638Y CN 02242404 CN02242404U CN2572638Y CN 2572638 Y CN2572638 Y CN 2572638Y CN 02242404 CN02242404 CN 02242404 CN 02242404 U CN02242404 U CN 02242404U CN 2572638 Y CN2572638 Y CN 2572638Y
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- circuit
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- overvoltage
- triode
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- 230000001681 protective effect Effects 0.000 title abstract description 8
- 238000005070 sampling Methods 0.000 claims abstract description 6
- 230000000087 stabilizing effect Effects 0.000 claims description 9
- 238000001514 detection method Methods 0.000 claims description 7
- 230000000977 initiatory effect Effects 0.000 abstract description 2
- 238000000034 method Methods 0.000 abstract description 2
- 230000003287 optical effect Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 5
- 230000003321 amplification Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
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Abstract
The utility model relates to an overvoltage protective circuit which is used for circuit protection. The utility model comprises a sampling circuit which is used for sampling detected input voltage V< i >, and a comparison circuit. The utility model is characterized in that the comparison circuit is composed of a three-end manostat TL431, the input end of the sample circuit is connected with the detected input voltage V< i >, the output end is connected with the reference end of the three-end manostat, and the cathode end of the three-end manostat TL431 is connected with an overvoltage signal triggering amplifying circuit; an ambipolar amplifying circuit of the overvoltage signal triggering amplifying circuit is composed of transistors Q1 and Q2, the output end is connected with a resistor R6, and thus an overvoltage protection trigger signal V< t > can be obtained; the resistor R6 is connected in series with an optical coupler which is used for initiating a trigger signal of the overvoltage protection. The utility model uses inherent characteristics of the three-end manostat TL431 for realizing the passivity method of an overvoltage protective circuit, and has the advantages of low cost, simple circuit design, and high operational reliability of the overvoltage protective circuit.
Description
Technical field
The utility model relates to circuit protection, relates in particular to a kind of overvoltage crowbar.
Background technology
Supply unit can the phenomenon of output overvoltage occur because of voltage stabilizing circuit loses efficacy, and not only can make the permanent failure of supply unit own in case overvoltage occurs, but also can injure the load equipment of supply unit.Solving overpressure problems has various measures, and some is that some is at the direct current overvoltage, the measure difference that different occasions is taked at the interchange overvoltage.
Be illustrated in figure 1 as common DC over-voltage protection circuit at present; it realizes that principle is: at first voltage signal is taken a sample; again the signal and the reference voltage that are sampled to are delivered to the comparator circuit that is made of elements such as operational amplifiers together; obtain the overvoltage protection triggering signal; this signal can be delivered to the next stage processing of circuit, realizes the purpose of overvoltage protection.
Overvoltage crowbar shown in Figure 1 is made up of five parts: sample circuit; comparison circuit; the overvoltage signal processing circuit; reference voltage; power circuit; such overvoltage crowbar generally needs active integrated chip; as amplifier; comparator etc.; therefore need power circuit; this power supply must be independent of outside the protected circuit; after being the protective circuit action; the protected circuit output voltage will be restricted; and the power supply of protective circuit should continue to keep normally; otherwise protective circuit can't be worked; so just limited the range of application of this protective circuit greatly; particularly in the circuit that input and output need be isolated; if adopt above-mentioned overvoltage crowbar; then not only need to adopt amplifier or comparator, increased cost, and need to increase by one tunnel external power source of isolating fully with input at least; improved the complexity of circuit design to a certain extent, and entire circuit has been increased immesurable influencing factor.
Summary of the invention
The overvoltage crowbar that provides a kind of cost low and simple and reliable is provided the purpose of this utility model.
The technical scheme that the utility model adopted is: this overvoltage crowbar comprises detecting input voltage V
iSample circuit of taking a sample and comparison circuit is characterized in that: described comparison circuit is made of three terminal regulator TL431, and the input termination of sample circuit detects input voltage V
i, the reference edge of output termination three terminal regulator TL431, the cathode terminal of three terminal regulator TL431 is connected an overvoltage signal triggering amplifying circuit with anode tap;
In the described overvoltage signal triggering amplifying circuit, PNP triode Q1 collector electrode links to each other with NPN triode Q2 base stage, triode Q1 emitter links to each other with triode Q2 collector electrode, triode Q1 base stage links to each other with the cathode terminal of three terminal regulator TL431 by resistance R 3, be connected resistance R 4 between triode Q1 base stage and the emitter, be connected resistance R 5 between triode Q2 base stage and the emitter, and triode Q2 emitter links to each other with resistance R 6, resistance R 6 other ends link to each other with the anode tap of three terminal regulator TL431;
Described resistance R 3 also connects the negative pole of voltage stabilizing didoe Z1, and the positive pole of voltage stabilizing didoe Z1 links to each other with the cathode terminal of three terminal regulator TL431;
Described triode Q1 emitter links to each other with diode D1 negative pole, the anodal and detection input voltage V of diode D1
iLink to each other;
Described resistance R 6 also is connected in series an optocoupler, and this optocoupler causes the triggering signal of overvoltage protection;
Described sample circuit is resistance R 1 and resistance R 2 serial connections, the detection signal V behind resistance R 2 voltage samplings
ChkThe reference edge of input three terminal regulator TL431.
The beneficial effects of the utility model are: the utility model utilizes the inherent characteristic of three terminal regulator TL431 to realize passiveization of overvoltage crowbar; promptly do not need the outside power circuit of design in addition; thereby simplified the overvoltage crowbar design; reduce cost, improved the functional reliability of overvoltage crowbar.
In the utility model, the overvoltage signal triggering amplifying circuit that employing is made of triode Q1 and triode Q2, simple in structure, and resistance R 3 links to each other with the cathode terminal 3 of three terminal regulator TL431, prevent circuit overvoltage infringement, also can between the cathode terminal 3 of resistance R 3 and three terminal regulator TL431, be connected in series voltage stabilizing didoe Z1, prevent circuit overvoltage infringement better, triode Q1 emitter by diode D1 with detect input voltage V
iCommunicate, simple in structure, improve functional reliability; Sample circuit adopts resistance R 1 and resistance R 2 serial connections, and simple in structure, cost is low, resistance R 6 serial connection optocouplers, and the triggering signal by optocoupler initiation overvoltage protection can further be applicable to the occasion that needs circuit to isolate.
Description of drawings
Fig. 1 is the overvoltage crowbar schematic diagram of prior art;
Fig. 2 is the utility model circuit theory diagrams;
Fig. 3 is the inner equivalent schematic diagram of three terminal regulator TL431;
Fig. 4 is embodiment 1 circuit theory diagrams;
Fig. 5 is embodiment 2 circuit theory diagrams.
Embodiment
With embodiment the utility model is described in further detail with reference to the accompanying drawings below:
Embodiment 1:
According to Fig. 2, Fig. 3 and Fig. 4, the utility model comprises detecting input voltage V
iSample circuit 11 of taking a sample and comparison circuit 44, comparison circuit 44 is made of three terminal regulator TL431, and the input termination of sample circuit 11 detects input voltage V
i, the reference edge 1 of output termination three terminal regulator TL431, the cathode terminal 3 of three terminal regulator TL431 is connected an overvoltage signal triggering amplifying circuit 22 with anode tap 2.
Be illustrated in figure 3 as the equivalent electric circuit of three terminal regulator TL431, its inside is equivalent to the integrated of amplifier, a reference source and a triode, voltage signal is imported by reference edge 1 after taking a sample, when voltage signal is higher than internal reference 2.5V, the then amplifier output level of three terminal regulator TL431 inside upset, the triode conducting, electric current can flow to anode tap 2 from cathode terminal 3, anode tap 2 links to each other with back level overvoltage signal amplification circuit with cathode terminal 3 again, can produce the overvoltage triggering signal.
As shown in Figure 4, detect input voltage Vi through sample circuit 11 samplings, sample circuit 11 be that resistance R 1 and resistance R 2 are connected in series, the detection signal V behind resistance R 2 voltage samplings
ChkThe reference edge 1 of input three terminal regulator U1; the cathode terminal 3 of three terminal regulator U1 is connected an overvoltage signal triggering amplifying circuit 22 with anode tap 2; overvoltage signal triggering amplifying circuit 22 constitutes two utmost point amplifying circuits by triode Q1 and triode Q2, and output connects resistance R 6, gets overvoltage protection triggering signal V
t
Overvoltage signal triggering amplifying circuit 22 is made of resistance R 3, R4, R5, R6 and PNP triode Q1, NPN triode Q2, PNP triode Q1 collector electrode links to each other with NPN triode Q2 base stage, triode Q1 emitter links to each other with triode Q2 collector electrode, triode Q1 emitter links to each other with the negative pole of diode D1, the positive pole of diode D1 and detection input voltage V
iLink to each other, triode Q1 base stage communicates with the cathode terminal 3 of three terminal regulator U1 by current-limiting resistance R3 and voltage stabilizing didoe Z1, resistance R 3 connects the negative pole of voltage stabilizing didoe Z1, the positive pole of voltage stabilizing didoe Z1 links to each other with the cathode terminal 3 of three terminal regulator TL431, be connected resistance R 4 between triode Q1 base stage and the emitter, be connected resistance R 5 between triode Q2 base stage and the emitter, and triode Q2 emitter links to each other with resistance R 6, resistance R 6 other ends link to each other with the anode tap 2 of three terminal regulator TL431.
When detecting input voltage V
iWhen overvoltage occurring, the detection signal V of dividing potential drop on resistance R 2
ChkWill be above three terminal regulator U1 internal reference voltage 2.5V; thereby make between the cathode terminal 3 of three terminal regulator U1 and the anode tap 2 and transfer low resistive state to by high-impedance state; form current path; the bias current of resistance R 4 causes triode Q1 conducting; further trigger triode Q2 conducting, the pressure drop of on state current on resistance R 6 constituted overvoltage protection triggering signal V
t, subsequent conditioning circuit is handled and can be protected system this signal.
Embodiment 2:
According to Fig. 2, Fig. 3, Fig. 4 and Fig. 5, for the occasion that needs are isolated, as shown in Figure 5, resistance R 6 also is connected in series an optocoupler, and this optocoupler causes the triggering signal of overvoltage protection, when detecting input voltage V
iWhen overvoltage occurring, the former limit of optocoupler led lighting triggers optical coupling secondary edges, starts overvoltage protection signal processing circuit 33.
In the present embodiment, circuit structure, operation principle and control procedure and embodiment 1 are described basic identical, repeat no more herein.
Claims (6)
1. an overvoltage crowbar comprises detecting input voltage V
iSample circuit of taking a sample (11) and comparison circuit (44) is characterized in that: described comparison circuit (44) is made of three terminal regulator TL431, and the input termination of sample circuit (11) detects input voltage (V
i), the reference edge (1) of output termination three terminal regulator TL431, the cathode terminal of three terminal regulator TL431 (3) is connected an overvoltage signal triggering amplifying circuit (22) with anode tap (2).
2. overvoltage crowbar according to claim 1; it is characterized in that: in the described overvoltage signal triggering amplifying circuit (22); PNP triode (Q1) collector electrode links to each other with NPN triode (Q2) base stage; triode (Q1) emitter links to each other with triode (Q2) collector electrode; triode (Q1) base stage links to each other with the cathode terminal (3) of three terminal regulator TL431 by resistance (R3); be connected resistance (R4) between triode (Q1) base stage and the emitter; be connected resistance (R5) between triode (Q2) base stage and the emitter; and triode (Q2) emitter links to each other with resistance (R6), and resistance (R6) other end links to each other with the anode tap (2) of three terminal regulator TL431.
3. overvoltage crowbar according to claim 2 is characterized in that: described resistance (R3) also connects the negative pole of voltage stabilizing didoe (Z1), and the positive pole of voltage stabilizing didoe (Z1) links to each other with the cathode terminal (3) of three terminal regulator TL431.
4. overvoltage crowbar according to claim 2 is characterized in that: described triode (Q1) emitter links to each other with the negative pole of diode (D1), the positive pole of diode (D1) and detection input voltage (V
i) link to each other.
5. overvoltage crowbar according to claim 2 is characterized in that: described resistance (R6) also is connected in series an optocoupler, and this optocoupler causes the triggering signal of overvoltage protection.
6. overvoltage crowbar according to claim 1 is characterized in that: described sample circuit (11) is connected in series for resistance (R1) and resistance (R2), the detection signal (V behind resistance (R2) voltage sampling
Chk) reference edge (1) of input three terminal regulator TL431.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02242404 CN2572638Y (en) | 2002-07-30 | 2002-07-30 | Overvoltage protective circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02242404 CN2572638Y (en) | 2002-07-30 | 2002-07-30 | Overvoltage protective circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2572638Y true CN2572638Y (en) | 2003-09-10 |
Family
ID=33714985
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02242404 Expired - Lifetime CN2572638Y (en) | 2002-07-30 | 2002-07-30 | Overvoltage protective circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2572638Y (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102035169A (en) * | 2009-09-28 | 2011-04-27 | 研祥智能科技股份有限公司 | Input overvoltage protection circuit and DC-DC power supply conversion device |
| CN102332704A (en) * | 2011-09-26 | 2012-01-25 | 中国兵器工业集团第二一四研究所苏州研发中心 | Switching power supply input undervoltage or overvoltage protection circuit |
| CN101515183B (en) * | 2009-03-30 | 2012-11-21 | 艾默生网络能源有限公司 | Output overvoltage regulating circuit |
| CN101119028B (en) * | 2007-06-28 | 2013-03-20 | 深圳市中兴移动通信有限公司 | Electrical source input overvoltage protection circuit |
| CN104948489A (en) * | 2014-03-25 | 2015-09-30 | 海洋王（东莞）照明科技有限公司 | Temperature control switching circuit |
| CN106385184A (en) * | 2016-09-30 | 2017-02-08 | 广西大学 | Adjustable switching power supply |
| CN106786462A (en) * | 2016-12-30 | 2017-05-31 | 福州福大海矽微电子有限公司 | A kind of amplifier switching mode overvoltage crowbar |
| CN106899206A (en) * | 2017-04-19 | 2017-06-27 | 长春汽车工业高等专科学校 | A kind of electric automobile is powered with high power D C DC converters and control method |
-
2002
- 2002-07-30 CN CN 02242404 patent/CN2572638Y/en not_active Expired - Lifetime
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101119028B (en) * | 2007-06-28 | 2013-03-20 | 深圳市中兴移动通信有限公司 | Electrical source input overvoltage protection circuit |
| CN101515183B (en) * | 2009-03-30 | 2012-11-21 | 艾默生网络能源有限公司 | Output overvoltage regulating circuit |
| CN102035169A (en) * | 2009-09-28 | 2011-04-27 | 研祥智能科技股份有限公司 | Input overvoltage protection circuit and DC-DC power supply conversion device |
| CN102035169B (en) * | 2009-09-28 | 2015-05-20 | 研祥智能科技股份有限公司 | Input overvoltage protection circuit and DC-DC power supply conversion device |
| CN102332704A (en) * | 2011-09-26 | 2012-01-25 | 中国兵器工业集团第二一四研究所苏州研发中心 | Switching power supply input undervoltage or overvoltage protection circuit |
| CN102332704B (en) * | 2011-09-26 | 2013-12-11 | 中国兵器工业集团第二一四研究所苏州研发中心 | Switching power supply input undervoltage or overvoltage protection circuit |
| CN104948489A (en) * | 2014-03-25 | 2015-09-30 | 海洋王（东莞）照明科技有限公司 | Temperature control switching circuit |
| CN106385184A (en) * | 2016-09-30 | 2017-02-08 | 广西大学 | Adjustable switching power supply |
| CN106786462A (en) * | 2016-12-30 | 2017-05-31 | 福州福大海矽微电子有限公司 | A kind of amplifier switching mode overvoltage crowbar |
| CN106786462B (en) * | 2016-12-30 | 2019-03-08 | 福州福大海矽微电子有限公司 | A kind of amplifier switching mode overvoltage crowbar |
| CN106899206A (en) * | 2017-04-19 | 2017-06-27 | 长春汽车工业高等专科学校 | A kind of electric automobile is powered with high power D C DC converters and control method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: NO. 1, KEJIGONGYEYUANKEFA ROAD, NANSHAN DISTRICT, Free format text: FORMER NAME OR ADDRESS: 518129 FLOOR 1, HUA WEI JI DI ELECTRICAL EQUIPMENT OR APPLIANCE FACTORY HOUSE, BAN XUE GANG INDUSTRY PARK, LONGGANG DISTRICT, SHENZHEN CITY, GUANGDONG PROV., HOUSE 3 |
|
| CP03 | Change of name, title or address |
Patentee address after: 518057 No. 1, FA Lu, Nanshan District science and Technology Industrial Park, Guangdong, Shenzhen Patentee address before: 518129, Guangdong Province, Shenzhen District, Longgang District HUAWEI industrial base, the first floor, the third floor of the electrical plant |
|
| C17 | Cessation of patent right | ||
| CX01 | Expiry of patent term |
Expiration termination date: 20120730 Granted publication date: 20030910 |